The present invention relates to flexible, collapsible receptacles known in the trade as "bulk storage bags." Typically, a bulk storage bag is used once as a disposable container for flowable or friable materials in bulk quantities and is then discarded, but the number of times such a container may be used or reused is unrelated to the present invention.
Typically, such bags are made of fabric such as a coarse weave of polyester, polyethylene, polypropylene, or other material of appropriate strength depending upon the size of the bag and the weight of the expected volume of contents. Bulk bags usually include some sort of handle or rings at their top portions so that the bag can be lifted by appropriate mechanical means such as a forklift or some other similar device.
In most circumstances, such bags also include an opening in their bottom portions from which the bag can be emptied. Such openings are covered and secured in a closed position when the bag is filled and transported. In order to open the bag and distribute its contents, the bag is usually lifted, and then the opening in the bottom portion is released or other-wise unsecured allowing the force of gravity to drain the bag's contents through the bottom opening. In some cases, a funnel, spout, or other shaped flexible portion is arranged to depend from the opening when the bag is opened.
A common disadvantage of such bags is that the bottom opening is usually located in the center of the bag's bottom panel. Typical bags form a solid rectangle (which can include a cubic shape) or a cylinder when filled. Because the bags are generally rather large in size; e.g. the bottom having dimensions of three or four feet in both length and width and a similar or greater height; the bottom opening is generally positioned approximately one-and-a-half or two feet inwardly from the vertical side edge of the bag. Thus, in order to open and empty such a bag, an operator must typically reach underneath the bag and unsecure its closure mechanism.
Given the large content volume of typical bulk bags, the task of manually reaching underneath such a bag and unsecuring the opening is often inconvenient, and potentially dangerous. At the same time, the closure over the opening must be secure enough to maintain the contents of the bulk bag in place during filling, handling, transport, and unloading operations. Accordingly, such well-secured openings that must be manually unsecured from underneath the center of a filled bag represents a significant problem in the use of such bulk storage bags.
Accordingly, there exists a need for such bags which can be maintained in a closed position during filling, transport, and other handling, but which can be more easily and more safely opened by an operator than can the presently available bags.